Fountain pen



1942- V L. MARTIN 2,303,374

FOUNTAIN PE Filed Nov. 3,.1941

I ymv MART/N.

Patented Dec. 1, 1942 1 UNITED STATES PATENT. OFFICE ropm'smrnu Lynn P.Martin; Fort Madison, Iowa, assignor to W. A. Sheaffer Pen Company, FortIowa, a corporation of Delaware Application November s, 1941, serial No.417,667 reclaims. (cl. 120-40) This invention relates to a fountain penand chambers, the amount of storage space being sufhas special referenceto the feeding mechanism flcient to accommodateconsiderably more than aof a fountain pen for directing writing fluid from normal expectantchange temperature and the reservoir thereof to the pen nib. pressureconditions.

More particularly, this invention relates to a 5 One of the objects ofthis invention is to profountain pen including a feed bar having a shank'vide 'afountain pen having a feeding mechanism portion adapted to bemounted within the bore capable of diverting the excess amount of fluidat the end of the barrel of the fountain pen and not necessary fornormal writing to storage a nib supporting portion extendingbeyond thchambers to eliminate flooding or leaking of the end of the barrel, thenib supporting portion be-- o o a p ing of substantially greaterdiameter than the Another object of s invention i8 60 Provide diameterof the shank portion. Means are proa fountain pen having ,a feedingmechanism vided in the feed bar for supplying writing fluid which issimple and eflicient in operation, is comfrom the'reservoir to the pennib. paratively j inexpensive to manufacture, and is In the normaloperation of a fountain pen, durable. i writing fluid is directed from areservoir within Other objects and advantages of this invention thebarrel thereof to the nib and therefrom onto will hereinafter be moreparticularly pointed out a writing surface, air being directed into theresand for a more complete understanding of the ervoir to take the placeof the writing fluid with characteristic features of this invention,referdrawn therefrom. The air in the fluid reservoir ence may now be hadto the following description of the barrel is effected by temperatureand presand the accompanying drawin in which latter: sure changes, andthe greater the amount of air Figure 1 is a front elevational view.greatly enin the reservoir and the lesser amount of writing larged, of afeed bar embodying the features of fluid therein, the more diflicult itis to control a thisinvention;

normal supply of writing fluid tothe writing sur- Fig. 2 is a sectionalI view taken on the line face. 2-2-0! Fig. i; 1

Heat from the hand when the fountain pen is Fig. 3 is a central verticalsectional view taken held in writing position tends to expand the air onthe line 3-3 of Fig. 1, a pen nib and pen behind the writing fluid. Ofrecent years, it has section being fragmentariiy shown in dotted beenthe tendency of fountain pen manufacturers lines; and

to increase the fluid capacity of a fountain pen. Fig. 4 is a sectionalview taken on the line l-l A larger capacity pen, of course, has alarger of Fig.3. amount of air to expand under comparable con- Referringnow more particularly to the draw-- ditions. The larger fluid chamber,holding a ing, the.feed barincorporating the features of comparativelygreater amount of air when parthe present invention comprises a shankportion tially filled, tends to supply a greater amount of II adapted tobe mounted within the bore at the wr ting fluid to the writing surfacethan is 118 end of the barrel of a fountain pen and a nib essary forordinary' writing, causing what is supporting portion ll adap ed toextend beyond called a flooding of the pen. if the f edi the end of thebarrel. The feed bar is for the mechanism is not capable of diverting acom- 40 purpose of directing writing fluid from the resparativelygreater excess of fluid from the writerv'oir within the barrel of thefountain pen to aing p i pen nib i2 shown in dotted lines in Fig. 3 ofthe The expansion of air behind the writing fluid drawing. The pen nibii in the present instance within the reservoir may, for example,accomhas a tubular shank portion I! which embraces pany a change oftemperature conditions, such inc. fixed relation a plug it. The plug llhas a as is attained in holding h pen in writing pohead portion and areduced threaded shank porsition after the fountain pen has beenmaintion II, the shank portion threadedly engaging tained at asubstantially lower temperature. Exthe internally threaded portion ofthe bore at pansion also accompanies a change of atmosthe end of thepen'section or barrel l5.

' ided with an internal duct pheric pressure, as when a fountain pen iscar- The feed bar is prov V I ried by a passenger in an airplane. Thpres- H which extends longitudinally thereof from the ent inventioncontemplates the elimination of reser o end to a point intermediate t enof flooding or leaking of the fountain pen by being the feed bar. A ventopening It extends transcapable of diverting fluid in excess of thatwhich Versely 0f the f bar and P ly Out de for normal writing intostorage the end of the ba.. ga g ll, the ventcpening is necessary fromthe nib supporting surface of the feed bar fiansversely through andbelow the internal duct it plurality of comb cuts 2| extend transverselyon the periphery of the feed bar and communicate with the fissure I. Inthe instance of the structure shown in the drawing, the comb cuts extendentirely about the circumference of the feed bar, although, it is to beunderstood, that it may be desirable in instances of use for the combcuts to extend but partially about the circumference of the feed bar oneach side of the fissure l9. The comb cuts are preferably of greaterwidththan the width of the fissure and extend over a major portion ofthe length of the. feed bar including the shank'portion II and the nibsupporting portion ll. Thus the comb cuts extend outwardly from. a pointwithin the bore at the end of the barrel. I

A plurality of cuts It extend longitudinally over a portion orthe-periphery of the feed bar for connecting a substantial number ofthecomb cuts and particularly those comb cuts disposed within the bore atthe end of the barrel. The

longitudinal cuts preferably connect all ofthe comb cuts within the boreof the end of the barrel and extend outside the end of the barrel to theatmosphere. In the drawing, three such longitudinal cuts have beenshown, the longitudinal cuts. being greater in width than the width ofthe co'mb cuts and being of lesserdepth than the depth of the comb cuts.

, The nib supporting portion of'the feed bar is for substantiallygreater diameter than the di-' ameter of the shank portionand'preferably' converges'in a direction outwardly from the barrel endof the fountain pen. The depth of the'comb cuts in both the shank andnib supporting portions of the feed bar terminate at substantially equaldistances from the axis of the feed bar so that the actual capacity ofthe comb cuts of the nib supporting portion is substantially greaterthan the comb cuts of the shank portion. The enlarged head or nibsupporting portion of the feed bar has the advantage, of'course, ofhaving a' much greater capacity than were the shank and nib s ppornsportions'or the same'or substantially the same external diameter andof the same length.

In the normal writing action of thefountain pen employing a feed bar nowin popular use.

when diverting excess fluid not necessary for normal writing operation,the fluid is conducted from the reservoir through an internal duct tothe fissure on the nib supporting periphery near the writing point end,theexceas fluid being directed into comb cuts at the writingpointendfirst and then progressively upwardly in the direction of the comb.cutinearest the reservoir end of the feed bar. It has been found thatthe height to which fluid could be raised and released to comb cuts inthis manner is materially limited and the capacity of the comb cutswithin such height is insuificient-for such abnormal conditions asshould be accommodated. g

. The present invention determines that the height to which fluid may bemaintained in the fissure and comb cuts of a feed bar when'in writ- 19on the feed being connected with the fluid reservoir and communicatingwith comb cuts within the end of the bore of the barrel as well as withthe comb cuts of substantially greater area on the nib supportingportion outside the end of the barrel 1 The comb cuts nearest thereservoir are filled by writing fluid as the fluid is drawn by capillaryattraction along the fissure I! in the direction of the writing pointand at the same time the comb cuts nearest the writing point end of thefeed bar fill in a direction upwardlytherefrom. In writing position,therefore, the comb cuts flll progressively inwardly from the endsthereof.

It has been found difilcult to conduct writing fluid into and out ofcomb cuts on the periphery of the feed bar within the bore of the end ofthe barrel. Such difliculty has been overcome in the provision of thethree longitudinally extending cuts 2| which are preferably spacedequi-distantly a from each other and connect the comb cuts inside thebore of the barrel, the, longitudinal cuts extending outside the bore ofthe barrel for communication with the atmosphere. By reason of thelongitudinally extending cuts being made slightly less in depth than thecomb cuts and slightly greater in width, the film strength of the fluidis weakened so that they are emptied by the cohesion of the fluid inthem with the fluid in the long connecting fissure II on the top of thefeed prior to the emptying of the comb cuts.

The longitudinal cuts, by reason of their dimensions, are'the last tofill with excess fluid, so that all of the .air previously contained inthe comb cuts within the bore of the end of the barrel that the ion:

and the provision of transversely ,extending comb cuts within the boreof the end of the barrel increases the capacity of the feed bar fordiverting excess writing fluid from the nib. However, to furtherincrease this capacity, the 'depth of the comb cuts is increased withoutweakening the structure of the feed bar. The central drilling I1 isprovided with the fissure l9 passing from the periphery of the feed barthrough and below the central drilling or so-called internal duct H. The.weakest fluid film is thus formed between the fissure and the centraldrilling or internal dust I1 somewhere between the lower end of thedrilling and the reservoir end thereof, and in order to make all thefluid contract back into the fluid chamber, it has been.found desirabieto have this weakest fiuid film formed near the front end of the centerdrilling.

The vent opening I8 is provided near the forward end of the internalduct H to connect the internal duct with the atmosphere and to locatethe point of weakest film formation thereat.

Thus, contraction from the front or writing point end is accomplished ina desirable manner and fluid which is in the comb cuts and longitudinalcuts within the bore of the end of the barrel is drawn by capillaryattraction out of the upper or back end of the fissure I9 where thefluid him is stronger than the film in the air vent, the air vent makingthe fissure purposely weak at the forward end of the internal duct ll.Fluid will be contracted back through the fissure at a point nearest thereservoir since the fluid film at that point will not break before thefllm at the air vent and the latter film will not break until the combcuts adjacent the writing point have emptied. Thus it is assured that anexpansion chamber free of fluid is formed capable of diverting excessfluid to its full capacity, should expansion occur after contraction.

In normal writing, when the expansion chain bers-that is, the transversecomb cuts andthe longitudinal cuts-are full, the comb cuts closest tothe reservoir empty flrst. When the expansion chambers are empty, fluidleaves the flssure I! at the writing point end and lipid taking theplace of that leaving the fissure at the writing pointend is directedfrom the reservoir in the bottom of the fissure l9 below the internalduct H in an unbroken condition and builds up in a direction irom thewriting point end toward the reservoir to control the air vent 18.

When contraction takes place due to cooling" of the air in the reservoiror to a change in atmospheric pres are full and the pen is carried withthe point directed upwardly, the comb cuts immediately adjacent thewriting 'point end of the feed bar are relieved of fluid first andthereafter the comb cuts are relieved progressively toward thereservoir'. Of course, if the expansion chambers are empty, suchcontraction will merely result in the intake of air. When a change-intemperature or atmospheric pressure is had, resulting in expan: sion, ifthe expansion chambers are empty and the fountain pen is held in anormal writing position, the comb cuts are filled with writing fluid inexcess of that needed for normal writing through the fissures above thecentral drilling to comb cuts nearest the reservoir and at the same timethrough fissure I8 below the internal duct ll to the comb cuts farthestfrom athe reservoir. This has been found to be normal, although thiscondition varies with a variance in the length of the feed bar and therate of expansion.

While but a single embodiment of this inven-.

tion is herein shown and described, it is to be understoodthat variousmodifications thereof may be apparent to those skilled in the artwithout departing from the spirit and scope of this invention, and,therefore, the same is only to be limited by the scopeof the prior artand the appended claims.

I claim:

l. A feed bar having a shank portion adapted to be mounted within thebore at the end of the barrel of a fountain pen and a nib supportingportion extending beyond said end of the barrel, said nib supportingportion being of substantially greater diameter than the diameter ofsaid shank portion, and means for supplying writing fluid fromsaidreservoir if) said pen nib.

2. A feed bar having a shank portion adapted to be mounted within thebore at the end ofthe barrel of a fountain pen and a nib supportingportion extending beyond said end of the barrel, said nib supportingportion converging in a direction outwardly from the barrel end andbeing of substantially greater diameter than the diamsure, if theexpansion chambers 80 eter of said shank portion, and means forsupplying writing fluid from said reservoir to said pen nib.

3. A feed bar having a shank portion adapted to be mounted within thebore at the end of the barrel of a fountain pen and a nib supportingportion extending beyond said end of the barrel,

greater diameter than the diameter of said shank portion, means forsupplying writing fluid from said reservoir to said pen nib, and combcuts extending transversely over at least a portion of the periphery ofboth said shank and nib supporting. portions of said feed bar.

'5. A feed bar having a shank portion adapted to be mounted within thebore at theend of the barrel of a fountainpen and a nib supportingportion extending beyond said end oilthe barrel, said nib supportingportion converging in a direction outwardly from the barrel end andbeing of substantially greater diameter than the diameter of. said shankportion, means for supplying writing fluid from said reservoir to saidpen riib, and comb cuts extending transversely over at least a portionof the periphery of both shank and nib supportingportions of said feedbar.

'6. A feed bar having ashank portion adapted to be mounted within thebore at the end of the barrel of a fountain pen and a nib supportingportion extending beyond said end of the barrel,

said nib supporting portion being of substantially greater diameter thanthe diameter of said shank portion, means for supplying writing fluidfrom said reservoir to said-pen nib, comb cuts extending transverselyover at least a portion of the periphery of both shank and nibsupporting portions of said feed banand longitudinally extending ductsdisposed peripherally of said feed bar intersecting comb cuts end of thebarrel.

7. A feed bar having a shank portion adapted to be mounted within thebore at the end of the barrel of a fountain pen and a nib supportingportion extending beyond said end of the barrel, said nib supportingportion being of substantially greater diameter than the diameter ofsaid shank portion, means for supplying writing fluid from saidreservoir to said pen nib, comb cuts extending transversely over atleast a portion of the periphery of both shank and nib supportingportions of said feed bar, and longitudinally extending ducts disposedperipherally of said feed bar intersecting comb cuts of both said shankand nib supporting portions.

8. A feed bar having a shank portion adapted to be mounted within theboreof the barrel of a fountain pen and a nib supporting portionextending beyond the end of said barrel, said nib supporting portionconverging in a direction outwardly from the barrel end and being ofsubstantially greater diameter than the diameter of said shank portion,a peripherally disposed longitudinally extending fissure on said shankand nib supporting portions for supplying writing within the bore at thefluidfrom said reservoir to said pen nib, comb,

cuts communicating with said fissure extending transversely over atleast a portion of the periphery of both shank and nib supporting por--tions of said feed bar, and longitudinally extending ducts disposedperipherally of said feed bar intersecting comb cuts of both said shankand nib supporting portions.

9. A feed bar having a shank portion adapted to be mounted within thebore at the end of the barrel 'of a fountain pen and a nib supportingportion extending beyond said end of the barrel, said nib-supportingportion being of substantially greater diameter than the diameter ofsaid shank portion, an internal duct extending longitudinally of saidfeed bar from one end thereof in .com-' munication with a writing fluidreservoir in said barrel to a point intermediate the ends thereof, and alongitudinally extending fissure of capillary dimensions in said feedbar extending from the reservoir end thereof to a point adjacent theother end thereof for supplying writing fluid to said nib, said fissureextending from the surface of said nib supporting portion transverselythrough and below said internal duct.

'10. A feed bar having a shank portion adapted Tm be mounted within thebore at the end of the barrel of a fountain pen and a'nib supportingbarrel to a point intermediate the ends thereof, a vent openingextending transversely of said a feed bar outside the end of said barreland communicating with said internal duct, and a longitudinallyextending fissure of capillary dimensions in said feed bar extendingfrom the reservoir end thereof to a point adjacent the other end thereoffor supplying writing fluid to said nib, said fissure extending from thesurface of said nib supporting portion transversely through and belowsaid internal duct. I

13. A feed bar having a shank portion adapted to bemounted within thebore at the end of the barrel of a fountain pen and a nib supportingportion extending beyond said end of the barrel,

I said nib supporting portion being of substantially portion extendingbeyond said end of the barrel,

' said nib supporting portion converging ln'a direction outwardly fromthe barrel end and being of substantially greater diameter than thediameter of said shank portion, an internal duct extendinglongitudinally of said feed bar from one end thereof in communicationwith a writing fluid reservoir in said barrel tov a point intermediatethe ends thereof, and a longitudinally extending fissure of capillarydimensions in said feed bar extending from the reservoir end thereof toa point adjacent the other end thereof for supplying writing fluid tosaid nib, said fissure extending from the surface of said nibsupportingportion transversely through and below said internal duct.

11. A feed bar having a' shank portion adapted to be mounted within thebore at the end of the barrel of a fountain pen and a nib supportingportion extending beyond said end of the barrel, said nib supportingportion being of substantially greater diameter than the diameter ofsaid shank portion, an internal duct extending longitudinally greaterdiameter than the diameter of said shank portion, an internal ductextending longitudinally of said feed bar from one end thereof incommunication with a writing fluid reservoir in said barrel, a ventopening extending transversely of said feed bar and communicating withsaid ina t'ernal duct, and a longitudinally extending fissure ofcapillary dimensions in said feed bar extending from the reservoir endthereof to a point adjacent the other end thereof, for supplying writingfluid to said nib, said vent opening being greater in diameter than thewidth of said fissure and said -fissure extending from the surface ofsaid nib supporting portion transversely through and below said internalduct.

14, A feed bar having a shank portion adapted to be mounted within thebore at the end of the barrel of a fountain pen and a nib supportingportion extending beyond said end of the barrel, said nib supportingportion being of substantially greater diameter than the diameter ofsaid shank portion, an internal duct extending longitudinally of saidfeed bar from one end thereof in communication with a wiring fluidreservoir in said barrel, a longitudinally extending fissure ofcapillary dimensions in said feed bar extending from the reservoir'endthereofto/ alpoint adjacent the other end thereof for supplying writingfluid to said nib, said fissure extending from the surface 'of said nibsupporting portion transversely through and below said internal duct,and comb V cuts extending transversely of said feed bar and being incommunication with said fissure, said of said feed bar from one endthereof in communication with a writing fluid reservoir in said barrel.to a point intermediate the ends thereof, a vent opening extendingtransversely of said feed bar and communicating with said internalgreater diameter than the diameter of said shank portion, an'internalductextending longitudinallyof said feed bar from one end thereof incommunication with a writing fluid reservoir in said comb-cuts being ofgreater width than the width of said fissure. I

15. A feed bar havinga shank portion adapted to be mounted. within thebore at the end of the barrel of a fountain penand a nib supportingportion extending bey ond said end of the barrel, said nib supportingportion being of substantially greater diameter than the diameter ofsaid shank portion, an internal duct extending longitudinally of saidfeed bar from one end thereof in communication with a writing fluidreservoir in said barrel, a longitudinally extending fissure ofcapillary dimensions in said feed bar extending from with'said fissure.

the reservoir end thereof to a point adjacent the other end thereof forsupplying writing fluid to said nib, said fissure extendingfrom thesurface .of said nib supporting poi-tion transversely through and belowsaid internal duct, and comb cuts extending transversely over at least aportion of said shank and nib supporting portions of said feed bar andbeing in communication LYNN P. MARTIN.

